| Explore | Drought stress can delay the germination rate and plant growth. Seed priming involves putting the seeds in a primer which can increase growth and germination. Also, seed treatments can counteract the negative effects of stress. |
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| Research Question | What is the effect of seed priming with osmo and hormone priming on growth and seed reserve utilization of millet seeds under drought stress? |
| Predictions | The seeds that are osmo or hormone primed will have a lower level of proline than seeds that are not primed. |
| Experimental Design | For osmo-priming, the seeds will be immersed in polyethylene glycol for 15 hours at 10° C and for hormone priming, seeds will be immersed in salicylic acid for 15 hours at 10°C under dark conditions. Then, the seeds will be rinsed with distilled water three times. Treated seeds will be surface dried for 24 hours. Seeds will be germinated in 9 cm petri dishes with two filter papers moistened with the appropriate solutions or distilled water for the control. WIth thirty seeds in each group: control, osmo-primed, and hormone-primed, they will be incubated at 25°C for 2 weeks. The germination rate and the seed reserve utilization will be measured. To measure seed reserve utilization, divide the seedling dry weight by the utilized seed reserve. The utilized seed reserve was calculated as the dry weight of the original seed minus the dry weight of the seed remnant (oven-dried weight of seedlings). To find the proline concentrations, first weigh 250 mg of a millet leaf sample. Conduct the rest of the process under the fume hood. Grind the sample with 10 mL of 3% Sulphosalicylic Acid with a mortar and pestle. Put the liquid sample into a test tube. Centrifuge the crude extract at 3000 rpm for 10 minutes. Transfer 2 mL of supernatant into a fresh test tube. Add 2 mL of 6M Orthophosphoric Acid using a micropipette to supernatant (Mix 6.05 mL of water with 3.95 of the 85% Orthophosphoric Acid to create a 6M Orthophosphoric Acid). Change pipette tip and add 2 mL of Acid Ninhydrin to supernatant. Change pipette tip and add 2 mL of Glacial Acetic Acid to supernatant. Keep it in water bath at 100 degrees Celsius for an hour. Transfer the solution into a separatory funnel. Change pipette tip and add 4 mL of Toluene and shake the solution well in the separatory funnel. Remove the bottom layer into another container that will be properly disposed of and keep the pink, upper layer in a test tube. Transfer enough liquid into a test tube that can fit into the spectrophotometer. Read the transmittance value at 520 nanometers for each sample and record the transmittance value. Use equation log10× 100/x, where x is the transmittance value. The resulting value is used to find the intersection point on the standard graph to find the proline concentration. |
| Conclusion | Priming will increase germination under drought stress which usually reduces plant growth. Results will show priming increases weight of utilized seed reserve, seedling dry weight, and germination rate compared to the unprimed seeds. |